Dispenser having a resilient sponge and piston



May 26, 1964 D. w. M. coPLEY DISPENSER HAVING A RESILIENT SPONGE ANDPISTON Filed Dec. 5, 1962 United States Patent 3,134,544. DISPENSERHAVHWG A. RESILENT SPONGE AND PISTGN David W. M. Copley, 3 Attunga Ave,Golflands,

South Australia, Australia Filed Dec. 5, 1962, Ser. No. 242,446 Claimspriority, application Australia Dec. 11, 1961 5 Claims. er zsa ss) Thisinvention relates to an improved means for the dispensing of volatileliquids and relates to the method of manufacture of such means.

In the dispensing of certain liquids, it is convenient to arrange thedispensing means in the form of a pump and furthermore it is convenientto arrange the dispensing means in the form of a sponge. Accordingly oneof the objects of this invention is to provide a dispensing meanswherein use is made of an absorbent sponge, and wherein use is made of apump principle so that a quantity of liquid is dispensed upon relativemovement of portions of the dispensing means. This feature of theinvention is achieved by means of a resilient sponge having an open cellstructure disposed beneath a pervious piston. The sponge can accordingto this invention be a polyurethane foam being of open cell structureand therefore capable of releasably containing the liquid to bedispensed. For example, the liquid to be dispensed could be a liquidwhich consists of or contains perfume or insect repellent or a mixtureof both.

In its simplest form the invention may be said to consist of adispensing means comprising a container having a base and sides butbeing open ended at its top, cover means releasably closing said opentop end, a resilient sponge having an open cell structure disposedwithin said container contiguous with its base, and a pervious pistonvertically movable in said container, whereby depression of said pistondisplaces liquid when retained in said sponge upwardly through saidpiston, but upon release of said piston said sponge urges said pistonupwardly.

When perfume is to be released, it is desirable that the rate ofevaporation should be limited by some means, and for this reason mostperfume which is sold in liquid form is diluted in some solvent, such asalcohol. In the case of a perfume dispenser for dispensing perfume tothe air however it is desirable to avoid the use of liquids in bottlesor other containers from which they can be spilt, and one of the furtherobjects of this invention is to provide a dispenser which will releasethe perfume at a sufliciently steady rate to be useful over a period ofdays or even Weeks instead of hours, and will retain the perfume liquidswithin a solid block. This feature of the invention is achieved by usinga piston formed from material which is porous so as to absorb theperfume, hygroscopic so that there is a partial pressure at the surfaceof the block caused by the moisture present and the perfume evaporationrate is thereby limited, non-poisonous so as to be safe, and possessinga long life so that it does not break down during storage.

A still further desirable feature of a perfumed dispenser is the abilityto control the rate of evaporation, and this is achieved in thisinvention either by control of the piston which constitutes pump meanswhereby perfume from the container is pumped into and through the pistonwhich if porous then becomes a perfume containing block.

An embodiment of the invention is described hereunder with reference toand is illustrated in the accompanying drawings, in which:

FIG. 1 is a central section through dispensing means showing cover meansclosing the open top of a container,

FIG. 2 is a side elevation of same showing the cover 3,134,544 PatentedMay 26, 1964 means removed from the open top of the container andforming a support therefor, and

FIG. 3 is a fragmentary section showing in exaggerated from theinterconnection between the container, cover and sponge retainingsleeve.

According to this embodiment, a liquid retaining sponge 1% is formed bytreating a resilient polyurethane foam (either polyether or polyester)in benzyl alcohol, whereupon the foam grows to several times itsoriginal size. The polyurethane sponge is treated by first depositing asmall annular piece within the cylindrical container 11 with the cover28 removed, then positioning the piston 12 in the container 11 and overthe sponge 10, then inserting the piston retaining sleeve 13 over theupstanding tubular stem 14 in the container 11, then riveting the upperend 15 of the stem 14 over the inturned annular lip 16 of the retainingsleeve 13.

A small quantity of benzyl alcohol is then placed in the cont ineraround the outside of the piston 12, and this quickly reacts with thepolyurethane foam sponge to expand it, thereby urging the piston 12upwardly against the retaining flange 20 of the piston retaining sleeve13. This then provides a pump return means for the piston 12, so thatthe piston 12 can be urged downwardly but springs backwardly under theforce exerted by the plastic memory of the ployurethane foam.

A sponge retaining sleeve 21 has on it a plurality of outwardly disposedannular ridges 22, one of the outwardly disposed ridges 22 engagingbeneath an inwardly disposed ridge 23 on the inner surface of thecylindrical container 11, while the lowermost ridge 22 sealably engagesthe inner wall of the container 11. Both the cylindrical container 11and the sponge retaining sleeve 21 are formed from resilient plasticmaterial so that the sleeve 21 .can be clipped in to the container 11.

The upper end of the sponge retaining sleeve 21 is turned inwardly anddownwardly to thereby form a sponge retaining lip 25.

An upper conical surface 26 on the sponge retaining sleeve 21 is engagedby an inwardly disposed ridge 27 on the cover 28 thereby providing meanswhereby the cover 28 can be clipped to the cylindrical container 11. Inthis embodiment the cover 28 is moulded in the same die as the container11, so that these two elements are of similar general shape.

In order to achieve conditions of more even rate of dispensing than canbe achieved with, say, a wick, the piston 12 is itself an absorbentmaterial adapted to contain a considerable quantity of perfume andrelease it slowly at a much steadier rate than heretofore. The piston 12is also slightly hygroscopic so that the partial pressure of moistureabsorbed by the piston 12 slightly represses the rate of evaporation ofthe volatile liquids contained within the piston 12. Furthermore thepiston 12 has a characteristic of molecular absorption of the volatileliquids when they are perfume or insect-repellent liquids, so that thefunction of pumping the piston 12 against the expanded polyurethane foamsponge 10 is to urge liquid into the piston 12 from the sponge 10.

In this embodiment the piston 12 consists of cellulose acetate incompressed granular form, each grain size being Within the range of fromone millimeter to two millimeter mean minimum dimension. The celluloseacetate grains are mixed in a rotary mixer with ethylene glycolmonoethyl ether (Cl-I OHCH OC H in the proportions of 2 parts celluloseacetate to 1 part ethylene glycol. The addition of the ethylene glycolmonoethyl ether is necessary to soften and swell the acetate so that infurther processing it can be compressed, bonding the granules into aporous block capable of absorbing the liquid rapidly, since the liquidcan quickly flow into the pores. The addition of the ethylene glycolmonoethyl ether also increases its hygroscopic tendencies, therebyassisting in the levelling out of the rate of the evaporation ofvolatile substances.

The ratio of 2 parts of cellulose acetate to 1 part of ethyleneglycolcanif desired be varied, whereupon the block will become either-more porousor more tightly compressed, but the ratio of 2:1 mentioned above isfound to besatisfactory for most practical purposes.

During the mixing, the ethylene glycol monoethyl ether is added in threestages, equal amounts being addedin each stage and at intervals of aboutone hour whilst the mixing continues. It is found desirable to allowcomplete absorption of the ethylene glycol monoethyl ether and'at thesame time prevent coagulation of the mix. At the end of the three hourmixing period the mix is in a condition where -it is dry but will notcoagulate when squeezed lightly in the hand, and in this condition it isfed into'a press where it is pelletized under a pressure of about 500kilogrammes per square centimeter. The block is then air-dried for aperiod of about 120 hours, before being impregnated with perfume andinsect-repellent.

As s'hown in FIG. 2, the cylindrical container 11 can be supported bythe cover 28 by simply inverting the cover which then engages with itsmouth disposed around the reduced diameter portion 30 of the cylindricalcontainer 11. If however it is desired to reduce the rate of dilfusionof the volatile substances from the piston 12, say for example if thedispensing means is to be used in a small room, the cover 28 can bepositioned loosely over the top of the piston 12 exposing portion onlyof its surface area to the atmosphere. This is a further control overthe rate of diffusion which is in addition to the control which isexercised by pumping of the piston 12 within the cylindrical container11.

A consideration of the above embodiment will indicate that thedispensing means is of convenient size and shape for packaging purposes,that it does not suffer with the disability of packaging in bottles inthat the liquid is retained within the expanded polyurethane foam spongeand cannot be readily spilt from the device. Further it will be seenthat the fingers can control the pumping action by being applied to theretaining flange 20 of the piston retaining sleeve 13, in which case thefingers need not necessarily have direct contact with the volatileliquids which are to be dispensed. Further it will be seen that thedispensing means consists of a cartridge which can be readily rechargedwith perfume or insect repellent if that is desired.

What I claim is: 1. Dispensing means comprising: a container having abase and sides but being open ended at its top, 7

a resilient sponge of polyurethane foam having an open cell structureand expanded with benzyl alcohol disposed within said containercontiguous with its base, and

a piston formed of mutually bonded cellulose acetate granules verticallymovable in said container above said resilient sponge whereby depressionof said piston displaces liquid when retained in said sponge upwardlyinto and through said piston, but upon release or said piston saidsponge urges said piston upwardly.

2. Dispensing means comprising:

a container having a base and sides but being open ended at its top,

a sponge retaining sleeve within said container,

a cover of resilient plastic engageable on said sponge sleeve,

' a sponge of open cell'structure resilient polyurethane foam expandedwith benzyl alcohol within said container near its base,

a piston composed of mutually bonded cellulose acetate granules disposedon top of said sponge, and piston a piston composed of cellulose acetategranules having a mean minimum dimension of between 1 and '2millimeters, softened with ethylene glycol monoethyl ether and mutuallybonded under pressure, said piston being disposed on top of said sponge,and piston retaining means fixed to the container retaining said pistonto said container,

whereby depression of said piston displaces liquid when retained in saidsponge upwardly into and through said piston, but upon release of saidpistonsaid spouse urges said piston upwardly.

4. Dispensing means comprising:

a container having a base and cylindrical sides but being open ended atits top, said cylindrical sides being of reduced diameter near the base,

an inwardly disposed ridge within said container near its open top,

a sponge retaining sleeve of resilient plastic within said container,

an outwardly disposed ridge on said sponge retaining sleeveengaging'said inwardly disposed ridge,

a cover of resilient plastic,

an inwardly disposed ridge on said cover engaging an outwardly disposedridge on said sleeve, said cover being removable from said sleeve andengageable on said reduced diameter portion near the base of saidcontainer to thereby support said container,

a sponge within said container near its base,

a piston composed of mutually bonded cellulose acetate granules disposedon top of said sponge, and piston retaining means fixed to saidcontainer retaining said piston to said container,

whereby depression of said piston displaces liquid when retained in saidsponge upwardly into and through said piston, but upon release of saidpiston said sponge urges said piston upwardly.

5; Dispensing means comprising:

a container of resilient plastic having a base and cylindrical sides butbeing 'open ended at its top,.said cylindrical sides being of reduceddiameter near the base,

an inwardly disposed ridge within said container near its open top,

a sponge retaining sleeve of resilient plastic within said container,

an outwardly disposed ridge on said sponge retaining sleeve engagingsaid inwardly disposed ridge,

an inwardly and downwardly turned annular sponge retaining lip on saidsponge retaining sleeve,

7 a cover of resilient plastic,

3,134,544 5 6 ether and mutually bonded under pressure disposedReferences Cited in the file of this patent on top of said sponge, acentral stem upstanding from said base, UNITED STATES PATENTS a pistonretaining sleeve slidable over said central 1,931,132 Hinckley 171 1933stem, and 5 1,954,893 Saeks Apr. ,17, 1934 a retaining flange on the topend of said piston retain- 2,418,035 Lachapelle 1947 ing sleeveretaining said piston to said container, FOREIGN PATENTS wherebydepression of said piston displaces liquid when retained in said spongeupwardly into and through said piston, but upon release of said pistonsaid 10 sponge urges said piston upwardly.

260,005 Italy Sept. 1, 1928 UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent N0 3,134,544 May 26 1964 David W, Mo Copley It ishereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 2, line 4 for "from" read form column 3 line 63 for "or" read ofcolumn 4 line 24, for "sponse' read sponge q Signed and sealed this 3rdday of November 1964,

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Aficsting Officer Commissioner ofPatents

1. DISPENSING MEANS COMPRISING: A CONTAINER HAVING A BASE AND SIDE BUTBEING OPEN ENDED AT ITS TOP, A RESILIENT SPONGE OF POLYURETHANE FOAMHAVING AN OPEN CELL STRUCTURE AND EXPANED WITH BENZYL ALCOHOL DISPOSEDWITHIN SAID CONTAINER CONTIGUOUS WITH ITS BASE, AND A PISTON FORMED OFMUTUALLY BONDED CELLULOSE ACETATE GRANULES VERTICALLY MOVABLE IN SAIDCONTAINER ABOVE SAID RESILIENT SPONGE WHEREBY DEPRESSION OF SAID PISTONDISPLACES LIQUID WHEN RETAINED IN SAID SPONGE UPWARDLY INTO AND THROUGHSAID PISTON, BUT UPON RELEASE OR SAID PISTON SAID SPONGE URGES SAIDPISTON UPWARDLY.